Device for feeding preheated air to combustion chambers



Patented Sept. 5, 1950 UNITED STATES PAENT OFFICE Frank A. Biegal, Buffalo, N. Y., assigner to Charles S. Doane, Sr.

Application August 2, 1948, Serial No. 42,124

Z Claims.

This invention relates to apparatus for delivering preheated air to combustion chambers and more particularly to apparatus of this type comprising a preheating unit which may readily be attached t the door of a furnace and swing with the door through the opening when the door is opened and closed.

An object of the invention is to provide an air feeding and preheating unit which may be attached to a furnace door and extend horizontally into the combustion chamber and so constructed and Varranged as to distribute heated air uniformly above the fuel bed to mix with and burn the unburned gases arising from the fuel bed.

Another object of the invention is to provide an air preheating unit of sim-ple and inexpensive construction formed to provide a tortuous passage to insure thorough heating of the air passing therethrough and which will divide and distribute the air stream evenly to all of the outlets therefrom to the combustion chamber.

A further object of the invention is to provide an air preheating unit for attachment to a furnace door including a housing of expanding volume in the direction of air ow therethrough having an end cap or closure tted on the end thereof, which cap is provided with a Y-shaped baille member, the stem of which divides the cap into two internal chambers and the arms of which cooperate, when the cap is in position on the end of the housing, with a pair of baille plates extending from opposite side walls of the housing to dene restricted air passages leading to the respective chambers in the cap from which the air is discharged to the combustion chamber.

Other objects and advantages of the invention will become apparent from the following detailed description of the invention with reference to the accompanying drawings which illustrate a preferred embodiment of the invention and in which,

Fig. 1 is a disjointed perspective view of the elements of the invention, and

Fig. 2 is a top plan View, with .parts in section showing the unit assembled and mounted on a furnace door.

Referring more particularly to the details of the drawings, I is an elongated main body or casing, preferably made of cast iron and substantially fiat and rectangular in vertical section. The end 2 of the housing I is closed by an integral end wall 3 which is provided with an external boss 4 and tapped centrally of the boss d as indicated at 5 for the reception of the threaded end of an air inlet pipe 6 which also serves to mount the unit on the furnace door 1.

lil

The air inlet pipe 6 extends through an opendrilled in the furnace door and has threaded on the projecting end thereof a hollow knob or cap 8 provided with an air inlet opening 9. It will be obvious that when the knob 8 is tightened on the end of the pipe t, the boss i will he seated tightly against the inner face of the furnace door and the unit will be securely fastened in place thereon.

Midway of the ends of the casing I, there are provided one or more baiile plates or partitions Iii to divert the air entering through the lpipe 5 in a tortuous path and against the side walls of the unit so as to be thoroughly heated by Contact therewith.

The projecting or forward end II of the casing I is flared laterally outwardly to increase the vol ume in the direction of air flow and is formed with forwardly extending bailie walls I2, one extending from each side wall toward the center, but terminating short of each other.

At the outer end of the flared end portion II, the casing is provided with a tapered shouldered seat I3 which receives a mating shouldered ange I4 of an end cap unit I5. Suitable threaded fasteners I6 passed through openings Il in the casing and engaging tapped openings i8 in the flange I4 of the end cap, secure the latter in position.

The end cap I5 is also preferably made of cast iron and is formed with an angular forward end face providing a central forward wall I9 and angularly disposed forward walls 2E), each of which is provided with a series of air outlet openings 2I. The angular disposition of the walls I9 and 20 provides for distribution of air to all parts of the combustion chamber.

The end cap I5 is formed with an integral Y-shaped baliie 22, the base or stem 23 of which extends rearwardly at right angles from the center of the wall portion I 9 and the arms 24 of which span the space between the ends of the baille I2 and extend parallel with and lie close in proximity to the baliie plates I2 defining therewith narrow passages 25 through which the air must flow in passing from the casing I to the cap.

The Y-shaped baffle 22 serves to divide the end cap I5 in half, forming with the walls thereof two identical chambers 26, as well as to divide the air stream flowing through the casing I into two streams which flow through the restricted passages 25 to the chambers Z and thence outwardly through the openings 2l. lIhus an even flow of air to all of the outlets 2| is assured. In passing through the narrow passages 25, the air is forced into close contact with the heated surfaces 3 Y of the baflie walls rand is thoroughly heated before passing into the combustion chamber.

The installation of the unit on existing furnace doors is very simple, all that is required being va hole sized to pass the pipe 6. The unit is installed on the door as close to the center as will permit the end to clear the'door frame when the door is swung open to charge the furnace.

While a preferred embodiment of the invention has been shown and described in detail by way of illustration, it will be understood that Various modications in the details of construction and assembly may be resorted to without departing from the spirit of the invention within the scope of the appended claims.

I claim:

l. An air feeder and preheater adapted for attachment to a furnace door to extend into the combustion chamber comprising an elongated hollow body having one end closed and tapped to receive a supporting air inlet pipe, said body flaring outwardly toward the opposite end there- Y of and formed with a pair of baffle members extending from opposite side walls toward but terminating short of the center thereof, a separate end cap unit removably secured to and closing the ared end of said body, said end cap having forward wall portions having perforations therein for outlet of air therefrom, and a baffle member carried by and removable as a unit with said end cap spanning the free ends of said first mentioned baffle members and defining therewith restricted air passages leading from said body to said cap when the latter is secured in position on the open end of the body.

2. An air feeder and preheater adapted for attachment to a furnace door to extend into the combustion chamber comprising an elongated hollow body having one end closed and tapped to receive a supporting air inlet pipe, said body flaring outwardly toward the opposite end thereof and formed with a pair of baille members eX- tending from opposite side walls at a forward angle with respect to but terminating short of the center line thereof, a separate end cap unit removably secured to and closing the flared end of said body, said end cap having forward wall portions having perforations therein for outlet of air therefrom, and a Y-shaped baffle member/ carried by and removable as a unit with said end cap the stem of which divides the cap into two chambers and the arms of which span the free Yends of the rst mentioned baffles and extend coincidently in parallel spaced relation with a portion thereof to define therewith restricted air' passages leading from said body to the chambers of said cap when the latter is secured on the flared end of said body.

FRANK A. BIEGAL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,153,273 Tacy Sept. 14, 1915 1,390,947 West Sept. 13, 1921 1,766,191 Russell June 24, 1930 

